Celtic stay top of the SPL table after both they and Hibernian were beaten on an unpredictable day in Scotland. Elsewhere, St Mirren won the bottom-of-the-table clash with Dundee.
Neil Lennon's Celtic side have been guilty of letting their Champions League adventure overshadow league form in recent weeks, and they suffered yet again as Inverness won 1-0 at Celtic Park.
Kris Commons and Mikael Lustig missed good chances for the home side in an otherwise dull first half but there was no second-half surge from the champions. After Billy McKay notched in the 65th minute from close range, he later spurned a good chance to double Inverness' lead when he hit the bar with only Fraser Forster to beat.
Hibernian could have gone top but they suffered their first loss at home this season, after they were edged out by Aberdeen 1-0 at Easter Road. Victory lifts Aberdeen second, level on points with their hosts in the table.
The home side were the better team throughout, with Craig Brown making a half-time tactical shuffle to try and shift the attacking flow in Aberdeen's favour. It made little difference but Aberdeen did find the winner, with Niall McGinn taking a couple of excellent short touches to move himself into a one-on-one situation with Ben Williams before coolly rolling the ball past the Hibs goalkeeper.
St Johnstone moved up to fourth after they beat Kilmarnock 2-1 at Rugby Park. Killie had to play 85 minutes with ten men after skipper Manuel Pascali was controversially sent off for a two-footed challenge, and Murray Davidson capitalised for the opener after 18 minutes. Michael Nelson's header appeared to have rescued a point for the home side in the 84th minute, but Rowan Vine won it in the 89th.
Motherwell drop out of the top four after they again failed to find the net at Fir Park, where they were held to a 0-0 draw by Hearts. The home side had the better of the second half after a poor first 45 minutes but their final ball was lacking.
The biggest moment of the match saw Hearts have a penalty claim rejected when Darren Randolph caught Callum Paterson with his knee as he collected a high ball. Referee Crawford Allan was the best-placed man in the stadium to judge and did not appear to think twice about ignoring the appeals.
St Mirren won the bottom-of-the-table battle with Dundee, opening up a four-point buffer between the two sides with a 3-1 victory. Colin Nish saw red midway through the first half for a dangerous challenge, and Steven Thompson took full advantage four minutes later with a close-range opener. Ryan Conroy's penalty levelled for Dundee, but Thompson grabbed his second with a 72nd-minute header before Dougie Imrie killed things off.
Elsewhere, Ross County were beaten 2-1 by Dundee United as they stayed below their opponents in the table. Iain Vigurs opened the scoring for County shortly after half-time with a glancing header, but Johnny Russell equalised immediately before Stuart Armstrong nodded in a Jon Daly knockdown for the winner.